1. Field of the Invention
The present invention relates to a process for producing vegetable protein foods having excellent flavour, taste, appearance and fibrous properties.
2. Related Art Statement
Processes for producing foods having a meat-like texture by processing soybean proteins by means of an extruder to form the meat-like structure have been known from the specifications of Japanese Patent Publication Nos. 6203/1969, 16778/1970, 2024/1975 and 25532/1975. The inventors developed previously a process for producing vegetable protein foods having a high-density multilayer structure and an excellent meat-like texture characterized by adding a starch and an oil to a main raw material which is an isolated soybean protein or alcohol leached concentrated soybean protein (Japanese patent application No. 65305/1985).
The products produced by the process of Japanese patent application No. 66305/1985 (for example, a food produced by mixing isolated soybean protein with potato starch in a ratio of 7:3 and adding an oil thereto) are excellent food materials, since when they are reconstituted with hot water, the starch, and a litte amount of soybean protein are removed and the fibrous properties thereof are exhibited to realize the meat-like texture, particularly elastic mouth feel like those of dried cuttlefish or scallop due to their structures per se or intertwinning of the fibers. These products are excellent food materials. Another advantage is that a part of the starch remains in the structure after the reconstitution with hot water and, therefore, the seasoning and coloring can be effected easily.
However, when the food produced by said process has a high water content, the texture is insufficient frequently. Another defect is that the structure is slimy due to the presence of the starch. To overcome these defects, an additional treatment step was necessitated. For example, the product was washed thoroughly with water for removing the slime after the reconstitution with hot water or a coagulating agent such as calcium sulfate is added thereto in the course of the reconstitution. Thus, the workability of said process is not fully satisfactory yet.